In prior luminaires, the parabolic reflectors that are mounted behind the fluorescent lamps and can rotate around the longitudinal axis of the lamp at the previous technical level are those reflectors that are supported on the fluorescent lamp through transverse louvers. The lamp passes through the circular openings of the louvers which are assembled on the reflector body. These reflectors do not rotate in steps in order to have fixed positions e.g. by 1°, 2° or 4°. Also, the reflector is not retained at a specific rotating position, since it is held in its place due to the friction developed between the internal surface of the louvers and the external surface of the lamp.
In accordance with the invention, a more accurate adjustment of the parabolic reflectors in certain positions around the imaginary axis of the fluorescent lamp could be ensured by the use of a system for the rotation of parabolic reflectors in steps. For e.g. 1° or 2° at various positions where the reflector can lock and cannot move, in case it is accidentally touched by human hand. As a result, it is easier to concentrate and direct the light beam reflected on the reflector from the fluorescent lamp. Such an adjustable rotation system for reflectors would be very useful if it could be easily incorporated into fluorescent luminaire housings using a simple procedure and without special manufacturing requirements for the luminaire housing or the reflector itself.
According to this invention, the reflector can be used inside luminaire housings where it can rotate around the fluorescent lamp by some degrees so that the light will be concentrated and directed as required, enhancing significantly the light performance of the luminaire and saving electric energy.